Title
Stress and Strain Distributions during Machining of Ti-6Al-4V at Ambient and Cryogenic Temperatures
Date of Award
2014
Degree Type
Thesis
Degree Name
M.A.Sc.
Department
Mechanical, Automotive, and Materials Engineering
First Advisor
Alpas, Ahmet T.
Keywords
Applied sciences, Chip formation mecahnism, In-situ machining, Instability criterion, Orthogonal cutting, Ti-6al-4v cryogenic cooling, Tool wear
Rights
CC BY-NC-ND 4.0
Abstract
Dry and liquid nitrogen pre-cooled Ti-6Al-4V samples were machined at a cutting speed of 43.2 m/min and at low (0.1 mm/rev) to high (0.4 mm/rev) feed rates for understanding the effects of temperature and strain rate on chip microstructures. During cryogenic machining, it was observed that between feed rates of 0.10 and 0.30 mm/rev, a 25% pressure reduction on tool occurred. Smaller number of chips and low tool/chip contact time and temperature were observed (compared to dry machining under ambient conditions). An in-situ set-up that consisted of a microscope and a lathe was constructed and helped to propose a novel serrated chip formation mechanism when microstructures (strain localization) and surface roughness were considered. Dimpled fracture surfaces observed in high-speed-machined chips were formed due to stable crack propagation that was also recorded during in-situ machining. An instability criterion was developed that showed easier strain localization within the 0.10-0.30mm/rev feed rate range.
Recommended Citation
Rahman, Md. Fahim, "Stress and Strain Distributions during Machining of Ti-6Al-4V at Ambient and Cryogenic Temperatures" (2014). Electronic Theses and Dissertations. 5048.
https://scholar.uwindsor.ca/etd/5048